Spatiotemporal drivers of crop pests and pathogens abundance at the landscape scale

The agricultural landscape has been recognized as a relevant scale for the control of bioagressors (pest and pathogen) epidemics. In this study, we assess the consistency of the impacts of semi-natural areas and host crop fields in the landscape on bioagressor abundance in cultivated fields. Our approach relied on the analysis of systematic French epidemiosurveillance data spanning 9 years of observations over two third of the French territory. 30 majors bioagressors of arable crops (wheat, barley, maize, potato, oilseed rape and sugar beet) were jointly studied with landscape composition as described by official CAP data and woody vegetation maps. Beyond the simple correlation between landscape composition and bioagressors abundance, we controlled for the presence of the host crop the former years in the plot and for bioagressors former prevalence. Our findings highlighted that landscape simplification around a same crop does not in general favor epidemic outbreaks during the current growing season, but rather that its harmful effect lie in the season ahead. The effects of semi-natural areas were, however, very contrasted between organisms. This study used available tools and data to quantify automatically in an interpretable way the general impact of landscape components. Such findings have relevant implications for the design of bioagressor management strategies at the landscape scale.